code: def test_iterator():
      """Tests the Dict `__iter__` function correctly returns keys in the subspaces"""
      for key in DICT_SPACE:
          assert key in DICT_SPACE.spaces
  
      assert {key for key in DICT_SPACE} == DICT_SPACE.spaces.keys()
  
file_path: gym/tests/spaces/test_dict.py
imports: from collections import OrderedDict
  import numpy
  import pytest
  from gym.spaces import Box, Dict, Discrete
label_desc: Use image node_id 7 for calling a global function with example usage: test_iterator() without return types